1. Field of the Invention
The present invention relates to snap-fit connectors, and more particularly to such connectors which are employed in fluid conduit systems to facilitate assembly and disassembly.
2. Description of the Art
Snap-fit or quick connectors have been found to be useful in a wide range of applications. In particular, they are frequently employed for joining fluid carrying conduits in automotive and industrial applications. Such connectors have found general acceptance as they are typically capable of being closed in a single uniaxial movement which facilitates automated assembly, and entail simple designs which are relatively inexpensive to produce.
A further advantage of quick connect fittings is that they provide an effective seal for handling volatile or hazardous fluids such as gasoline while permitting ease of disassembly and reassembly during repair of a host system. Although tools are often required to effect release of quick connect fittings, designs such as those described in U.S. Pat. Nos. 3,990,727, 4,844,512 and 4,991,882 provide for manual release of the fitting without the necessity of separate tools. Although representing an advancement in the art, such "squeeze-to-release" designs often have certain shortcomings.
In applications where hazardous material is to flow through a fitting, prevention of inadvertent release is of primary concern. Accordingly, relatively high axial pull-apart strength specifications are mandated. In order to comply with such specifications, manufactures of prior art designs typically employed material with a relatively high characteristic flex modulus (such as glass filled Nylon 12) to prevent warping or deformation of abutting locking surfaces within the connector under axial loading conditions. Unfortunately, materials with increased flex modulus are inherently stiffer and can require substantially higher release forces. A related problem is found in that the stiffer material tolerates only relatively short radial displacement of the female connector abutment surface to effect release. This provides relatively little "purchase" (or degree of radial overlap) of the mating abutment surfaces in the engaged condition, thereby exacerbating potential pull apart problems.
Lastly, known prior art designs were prone to fatigue leading to failure after a relatively small number of engagement-disengagement cycles.
The squeeze-to-release quick connector shown in U.S. Pat. No. 5,213,376, assigned to the assignee of the present invention, was designed to overcome these shortcomings. This connector has a pair of parallel arranged beam members, each affixed at one end to a retaining ring and at the other end to a mount located on the outside surface of the body portion of a female connector member and axially spaced from the open end of the female member. Two or more spaced detents extend inwardly from the retaining ring to capture an abutment surface of a male connector member to effect positive axial engagement between the female and male members. The beam members preferably extend axially a distance approximately equal to the characteristic inner diameter of the body portion of the female member.
While the connector shown in U.S. Pat. No. 5,213,376 provides positive axial engagement and quick and easy squeeze release of the two connector members, it would be desirable to further improve this connector with respect to greater flexure of the beam members for an easier squeeze release with less force; while still retaining positive axial engagement between the two connector members and a high pulloff strength when the connector members are in their connected state.